Abstract: Objective To investigate the prevalence and influencing factors of recurrent respiratory tract infection(RRTI)among preschool children in Mudanjiang city,Heilongjiang province,and to provide references for prevention and treatment of RRTI in children.Methods Totally 1 583 non-boarding preschool children were selected from 18 kindergartens in Mudanjiang city from September 2015 to September 2016 using random cluster sampling.A self-designed questionnaire was used to survey the guardians of the pre-school children on the prevalence of RRTI.Results Of the 1 583 preschool children,432 (27.29%) were reported with RRTI.Of the 432 RRTI cases,236 (54.63%) and 196 (45.37%) were with recurrent upper and lower respiratory tract infection.Multivariate unconditional logistic regression analysis showed that having snack intakes of ≥7 times per week,cohabitation with smokers,suffering from asthma,and with family members having chronic respiratory tract disease were risk factors for RRTI;while,taking vegetables ≥7 times per week and having outdoor activity two hours or more per day were protective factors against RRTI.Conclusion The prevalence of RRTI is serious and influenced by snack consumption,whether cohabitating with a smoker,whether suffering from asthma,having a chronic respiratory tract disease patient in the family,the amount of vegetables intake,and time of outdoor physical exercise for the preschool children in Mudanjiang city.